Doubts on "PC-based DVR vs Standalone DVR"

[wishmegood 0]

Hi all, I have a big doubt on 'pc-based DVR vs standalone DVR'.

I had commissioned a cctv system recently, which includes 16 units of 1/3" Sony Colour Dome Camera, 420TVL and a pc-based Geovision Card, GV800.

 

While testing all these camera with a television, they could display clearly. Yet, while I connected them to the GV800, the resolution obviously decreased; somehow, even I connected only one camera to this 16-channel Geovision DVR card with less than 1 meter of Belden RG59 coaxial cable between DVR and PC, the image quality is still much poorer than the condition I connect the same camera directly to a television. What could be explained about this? I didn't know how to explain to the customer that I showed them the camera could display clearly before we started the installation, but now the image quality is bad! I had configured the settings inside the GV800 to be the best for monitoring and recording already.

 

Is it possible that, Geovision couldn't give enough resolution up to 420TVL while using the aforesaid 1/3" Sony Colour Dome Camera, 420TVL? If so, with this condition, I change all the cameras to be 1/3" Sony Colour Dome Camera, 520TVL, the image quality could increase a bit, but not up to 520TVL too, right?

 

Is there any other better solution, other than using GV800 / GV900? Will a 16-Channel Standalone DVR, pentaplex will give better result?

 

Thank you very much for your advices!

[rory 0]

If you are using an LCD monitor this is normal. The live video quality (LCD or CRT) will be somewhat less than the raw composite either way, but the LCD makes it look worse, has nothing to do with the actual recorded video though, and evidence sharing is much better with the Geo than most stand alones. Also, if you are using VGA on the LCD then it wont be as clear as if you were to use the DVI.

 

If you want same quality live video, you would need the combo card with the DSP composite video output.

 

And LOL @ pentaplex, ignore that as it means very little these days.

 

Also, I doubt that is an Actual Sony Dome? Either way, 420TVL is medium resolution, but its the Effective Image Pixels that really matter and even with a cheap OEM dome that claims High Res, does not mean you will be getting the correct Image Pixels, so you would need a decent name brand dome.

 

Yes though, a truly high resolution camera will produce a higher resolution image in the GeoVision software, depends on the camera itself as to whether or not the image itself is actually better though (lighting issues, etc, can also degrade quality).

[tesc_cctvpro 0]

Agree with previous poster.

 

Firstly -- most cameras coming out of china that are labelled 420TVL are not actually so.

 

Secondly, LCD's tend to look worse than a CRT monitor for example.

 

Regarding the 520TVL camera, these high resolution cameras are only as good as your display device. TV's and LCD monitors are not usually able to reproduce that kind of resolution.

 

I think though that none of this explains why the images are clear on the TV, and poor on the DVR display.

 

I suggest that you connect a CRT monitor to your PC if you are using an LCD monitor. If the image is better on the CRT, then it's probably because you are using an LCD monitor - Lcd's don't always give the best surveillance result.

 

If you want to use LCD's then you need to pay attention to the LCD specifications, such as contrast ratio's, and refresh rates. Nothing beats a proper security monitor though, which can handle 500+ TVL resolutions.

[forbus 0]

I don't know how pixelated your picture is but is normal that the PC based DVR system does not show that same camera image on TV. When you feed the camera to the TV, you get the raw (unprocessed) video. Any camera connected to any PC based DVR will show some pixelation and this is normal with analog cameras and current DVR cards on the market. The embedded DVR's will most probably show you pretty much the same raw video image but as soon as you playback any video file, you wil see the pixelation again because the playback video is from a digital file. So, what you experience is totally normal. I posted a very similar video on this forum about 2 years ago when I installed my first DVR.

[phuketall 0]

i have combo card now and there is a big difference in output, question on another front, what is a decent quality dome the is relatively inexpensive?